An Indian diagnostic laboratory case report on mosaic chromosome 18 (original) (raw)
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BMC Medical Genomics
Background A plethora of cases are reported in the literature with iso- and ring-chromosome 18. However, co-occurrence of these two abnormalities in an individual along with a third cell line and absence of numerical anomaly is extremely rare. Case presentation A 7-year-old female was referred for diagnosis due to gross facial dysmorphism and severe developmental delay. She presented with dysmorphic features, hypo/hyper pigmentation of the skin, intellectual disability and craniosynostosis. G-banding chromosome analysis suggested mos 46,XX,psu idic(18)(p11.2)[25]/46,XX,r(?18)[30]. Additional analysis by molecular karyotyping suggested pure partial deletion of 15 Mb on 18p (18p11.32p11.21). Lastly, multiple rearrangements and detection of a third cell line (ring chr18 and interstitial deletion) of chr18 was observed by multi-color banding. Conclusion The current study presents a novel case of chromosomal abnormalities pertaining to chromosome 18 across 3 cell lines, which were deline...
18q Deletion Syndrome – A Case Report
Journal of Medical Science And clinical Research, 2016
The 18q deletion syndrome is among one of the commonest cytogenetic abnormalities with an incidence of 1 in 40000 live births without any ethnic predilection. Here we a present a with multiple dysmorphic features like micrognathia, large forehead, flat midface, hypertelorism, prominent antihelix, moon face with full cheeks were recognized, flat nasal bridge, thin lips and short neck and overlapping of the fingers. A MRI brain was done which showed enlarged ventricle with abnormal signal intensities in bilateral frontal and periventricular region. High resolution and G-banding chromosome analysis using peripheral lymphocytes was performed due to her many symptoms, which revealed a unique karyotype of 46, XX, del 18q3.1.
Minor dysmorphism in a child with inherited ring chromosome 18
Medical Research Journal, 2013
The most frequent structural abnormalities of chromosome 18 are deletions and ring chromosome. Clinical features of ring chromosome 18 depend on the extent of the deleted chromosomal segments, the 18p and 18q deletion syndromes. We report on a 6-year-old female child who was presented to the children with special needs clinic, the National Research Center, with a complaint of hyperactivity and occasional episodes of loss of concentration simulating atypical absence seizure. She had a minor nonspecific pattern of dysmorphism and growth retardation; height, head circumference, and body weight measurements were below 2.5 SD. Electroencephalography for the child indicated generalized epileptogenic discharge whereas brain MRI did not indicate any abnormality. Cytogenetic analysis of the patient showed 46,XX, r(18)(65%)/46,XX, double size r(18)(35%); the mother showed the 46,XX, r(18) karyotype in all studied metaphases whereas her father showed the normal male karyotype 46,XY. Fluorescent in-situ hybridization showed that the ring chromosome 18 had deletion of both 18p and 18q subtelomeres. The transmission of ring chromosome 18 from the mother to her daughter with a mosaic karyotype of double-size ring chromosome that resulted only in minor dysmorphism has not been documented in previous studies.
Cytogenetic investigation of a child with a mosaic isochromosome 18q and ring 18q
European Journal of Medical Genetics, 2007
We report on a baby girl from non-consanguineous Palestinian parents with intrauterine growth retardation, low birth weight, and developmental delay. She had a short stature, microcephaly, a prominent metopic suture, a glabellar haemangioma, exophthalmos, hypertelorism, upslanting palpebral fissures, horizontal nystagmus, flat nose, cleft lip and palate, a short neck, widely spaced nipples, umbilical hernia, flexion deformity of the wrist, ulnar deviation of fingers, and right club foot. Cortical atrophy, enlarged ventricles, a thin corpus callosum, thoracic hemivertebrae, and a ventricular septal defect were detected as well. High resolution chromosome analysis identified in 92% of cells an isochromosome 18 and in 8% of cells a ring 18. Molecular cytogenetic investigations confirmed that it was an i(18q) and a r(18q). The hypothesis to account for this anomaly and its corresponding phenotype are discussed.
Case report of de novo dup(18p)/del(18q) and r(18) mosaicism
Journal of Human Genetics, 2008
This is a report of a 27-year-old woman with an unusual de novo chromosomal abnormality. Mosaicism was identified in peripheral blood cells examined by standard G-bands by trypsin using Giemsa (GTG) analysis and fluorescence in situ hybridization (FISH) analysis with chromosome-18 region-specific probes, 46,XX,del(18)(pter ? q21.33:)[41], 46,XX,r(18)(::p11.21 ? q21.33::)[8], and 46,XX,der(18)(pter ? q21.33::p11.21 ? pter)[1]. On the other hand, the karyotype of periodontal ligament fibroblasts was nonmosaic, 46,XX, der(18)(pter ? q21.33::p11.21 ? pter)[50]. All cell lines appeared to be missing a portion of 18q (q21.33 ? qter). The pattern of the dup(18p)/del(18q) in the rod configuration raises the possibility of an inversion in chromosome 18 in one of the parents. However, no chromosomal anomaly was detected in either parent. The most probable explanation is that de novo rod and ring configurations arose simultaneously from an intrachromosomal exchange. The unique phenotype of this patient, which included primary hypothyroidism and primary hypogonadism, is discussed in relation to her karyotype. Keywords Deletion 18q Á Ring chromosome 18 Á Rod/ring mosaicism Á Hypothyroidism Á Hypogonadism
Clinical and molecular-cytogenetic studies in seven patients with ring chromosome 18
American Journal of Medical Genetics, 2001
We report here a child with a ring chromosome 5 (r(5)) associated with facial dysmorphology and multiple congenital abnormalities. Fluorescent in situ hybridization (FISH) using bacterial artificial chromosome (BAC) clones was performed to determine the breakpoints involved in the r(5). The 5p deletion extended from 5p13.2-3 to 5pter and measured 34.61 Mb (range: 33.7e35.52 Mb) while the 5q deletion extended from 5q35.3 to 5qter and measured 2.44 Mb (range: 2.31e2.57 Mb). The patient presented signs such as microcephaly, hypertelorism, micrognathia and epicanthal folds, partially recalling those of a deletion of the short arm of chromosome 5 and the "cri-du-chat" syndrome.